Elevator leveling means



April 17, 1956 o. F. SCHNABEL EI'AL 2,742,108

ELEVATOR LEVELING MEANS 4 Sheets-Sheet 1 Filed Feb. 24, 1955 Hoof" Hoar 5 mm i m m r Z M w 6% no ffi fl r aw e 7% M My 1 F 1 w p f 5 WW April 1956 o F. SCHNABEL HAL 2,742,108

ELEVATOR LEVELING MEANS 4 Sheets-Sheet 2 Filed Feb. 24, 1955 c/0/727 7V V/c/Per's WM The/J" fltorweys April 1956 o. F. SCHNABEL ET AL 2,742,108

ELEVATOR LEVELING MEANS 4 Sheets-Sheet 3 Filed Feb. 24, 1955 V/cfers f2? Men tor-s Otto F5c/7/7afie/ April 1956 o. F. SCHNABEL ETAL 2,742,108

ELEVATOR LEVELING MEANS Filed Feb. 24, 1955 4 Sheets-Sheet 4 30 fr; vex? torus 9521b FSchnabd Job)? 7 V/b/(fe/"s MVM 77/e/r' fitter)? eys i F/a.

United States Patent ELEVATOR LEVELING MEANS Otto F. Schnabel, New York, and John H. Vickers, 'Hudson, N. Y., assignors to Giti'ord-Wood C0,, Hudson, N. Y., a corporation of New York Application February 24, 1955, Serial No..490,3,28.

9 Claims. (Cl. 187'-29) Our relation relates to elevators and particularly to material carrying elevators whichdo not carry an operator and which are operated by push. buttons at. the. various floors served thereby.

In elevators of this type it is very important that the carriage shall stop automatically, substantially precisely at the floor level to which it is sent.

The principal object of our invention is to provide means for automatically stopping an. elevator of the. push button operated type when the carriage is substantially precisely at the level of the floor to whichit has been sent. A further object is to provide an elevator of this type the carriage of which may be sent from any floor to any of the other floors served thereby and which will automatically stop at the level of the floor to which it is sent.

We accomplished these objects by the means described below and illustrating in the accompanying drawings in which- Fig. l is a diagrammatic elevation view of an elevator according to our invention which serves three floors;

Fig. 2 is a diagrammatic perspective view of the carriage showing the main hoisting and lowering motor, and a second motor and the mechanism driven thereby for stopping the carriage at a precise point; V

Fig. 3 is a vertical section through the leveling screw;

Fig. 4 is an elevation view showing a portion of the leveling screw and the motor which drives the nut cooperating with the screw for moving it up and down;

Fig. 5 is a top plan view ofthe elements shown in Fig. 4 with a portion of the motor broken away;

Fig. 6 is a section of Fig. 3 in the plane 66;

Fig, 7 is a section of Fig. 3 in the plane 7-7;

Fig. 8 is a side elevation of the elevator drawn to a somewhat different scale from that of Fig. 1;

Fig. 9 is a right side elevation of the upper portion of the elements shown in Fig. 8;

Fig. 10 is an enlarged top plan view;

Fig. 11 is a wiring diagram showing the various relays,

switches and circuits by means of which the operation of the elevator is controlled;

Fig. 12 is a top plan view or" a rotary limit switchwith the cover removed and showing only the switches and the cams which operate the same;

Fig. 13 is a section through the cams in the plane'1-3 13 of Fig. 12; and

Fig. 14 is a section similar to Fig. 1414 of Fig. 12.

Referring to the drawing-- 1 is the carriage of the elevator which moves up and down in the shaft 2. At the top, the carriage is provided with a pulley 3 through which the cable 4 runs. One end 13 but in the-plane of the cable is attached to the winding drum 5 which is driven by the reversible motor 6 and the other end thereof is attached to the lower end of the vertically disposed leveling screw 7. 7

Referring now more particularly to Figs. 3, 4 and 5,

the screw 7 cooperates with a nut 8' which is rotatably mounted in the bearing 9 at the top of the shaft. The

not 8 has-a gear 10 secured thereto and also a sprocket wheel 11. The combined gear 10 and sprocket 11 are driven by the reversible motor 12 through the spur gear 13'. A. chain 14 is driven by the sprocket 11 and serves to drive the two sprockets 15 and 16 which are best shown in Fig. 5 and the function of which will be explained below.

In order to guide the screw 7 and to prevent binding in the nut 8, the lower portion 17 thereof is not threaded and slides through the bushing 18. Adjacent the threaded portion. of the screw there are attached guide rollers 19 and 20 which run between the flanges of the channel guides. 21 and 22 to prevent rotation of the screw (see also Fig. 7). An eye 23, to which one end of the cable 4 is attached, is provided, at the lower end of the screw.

Referring now more particularly to Fig. 11 which shows the various switches and circuits by means of which the motors 6 and 12 are energized and de-energized, 12 and 13 indicate push button switches at the first floor which, when pressed, will move the armatures of relays 24 and 25,. respectively, upwardly and close the necessary circuits to send the carriage either to the second floor or the third floor, respectively. 21 and 2-3 are similar switches at the second floor which move the armatures of relays 26 and 27, respectively, to send thev carriage from the second to either the first or third floor, respectively. 3-1 and 32 are similar switches at the third floor which move the armatures of relays 28 and 29, respectively, to send the carriage down to either the first ,or second floor, respectively. These switches are shown diagrammatically in Fig. 1 at the side of the elevator shaft. 30 and 31 are the main power lines. UP is a solenoid switch which, when energized, closes a circuit (not shown) to start the main motor 6 in a direction to raise the carriage, and DN is a solenoid switch which, when energized, closes a circuit (not shown) to start the main motor to lower the carriage. SUP and SDN are solenoid switches which, when energized, close circuits (not shown) to start the motor 12 to move the screw 7 up and down, respectively.

32'and 33 are rotating limit switches which are operated by cams and 86, driven by the sprockets 15 and 16 (see Fig. 5), and both of which are normally open, as shown in Fig. 12, when the leveling screw 7 is centered in the nut. But when the screw moves upwardly from its center position,.switch 32 closes while 33 remains open and, when the screw moves downwardly from its center position, switch 33 closes while switch 32 remains open.

Switches 34 and 35, which are not shown in detail, are normally closed but 34 is automatically opened to prevent over travel of the screw when it moves downwardly, and 35 is automatically opened to prevent over travel of the screw when it is moving upwardly.

IDSD is a switch actuated by the elevator when the carriage is moving downwardly and is near the first floor to slow down its movement by breaking the circuit through the main motor 6 and closing a circuit through switch SDN which, in turn, closes a circuit through the motor 12 to move the screw downwardly.

IDST is an elevator actuated switch which opens when the carriage is substantially precisely at the first floor level. This last mentioned switch is really three switches and the solid black portions 36 indicate insulation separating, these switches. Switches 1DSD and IDST (abbreviations. for first floor down-slow-down switch and first floor down-stop switch) and the means 87 on the carriage which actuate them and similar switches on the second and third floors are shown in Fig. l.

2DSD isa switch similar to IDSD which is actuated by carriage is close to the second floor and close a circuit a) through the motor 12 which takes over the downward movement of the carriage through the leveling screw 7 until it is substantially precisely at the level of the second floor. ZDST is an elevator actuated switch similar to lDST which functions to shut cit the motor 12 and stop the screw.

Since the carriage may be sent to the second floor either down from the third floor or up from the first floor, 2 USD is a switch similar to 2138]) but functions to slow down the carriage when it is being sent upwardly from the first floor to the second floor, and ZUST is an elevator actuated switch which is opened to shut off the motor driving the leveling screw when the carriage is substantially precisely at the second floor level where it is to stop.

3USD is a switch actuated by the elevator when the carriage is moving upwardly and close to the level of the third floor to shut off the main motor and energize the motor 12 to move the screw upwardly; and 3UST is the elevator actuated switch which functions when opened to stop the motor 12 when the carriage is substantially precisely at the third floor level.

In operation, assuming that the carriage is at the first floor and is to be sent to the second floor, and bearing in mind that the screw has moved downwardly from its cen ter position and stopped in a down position when the carriage was stopped at the first floor, if push button 1-2 is then pressed, relay 24 will be energized by current flowing from the main line 30 through conductor 37, the winding of relay 24, push button l2, conductor 38, through ZUST, conductor 39, relay 25, conductor 49, relay 26, conductor 41, relay 27, conductor 42, relay 28, conductor 43 and relay 29 to main line 31. When push button 1-2 is released, and bearing in mind that the winding of relay 24 has been energized and the armature thereof has moved upwardly, it will remain energized by the closing of the circuit through conductor 37, the winding of the relay 24 and the conductor 44 which takes the place of the switch 12.

When the relay 24 is closed, conductors 45 and 46 will be connected to the main line 31. If conductor 46 is followed, it will be apparent that no current can flow there through until switch 2USD is moved by the elevator. However, if conductor 45 is followed, it will be clear that current may flow therethrough to switch 2USD, thence through conductor 47, switch 48, which is an up, overtravel, limiting switch and normally closed, through the armature of switch DN, conductor 49, the winding of switch UP to main line 3% through the overload circuit breakers 50. The closing of the switch UP also energizes the solenoid switch MS through conductor 51. When the carriage stopped at the first floor on its previous trip, the

I leveling screw stopped in a down position and, while it would not be necessary in this particular case to center the screw before the next stop where it would have to move upwardly at the second floor, this is not the case in other instances, and we have, therefore, so designed our elevator that the screw will be automatically centered after each stop and before the carriage stops at the next floor to which it is sent. This will be clear, for example, by considering the case where, after the carriage has been sent from the first to the second floor and the screw has moved upwardly to stop the carriage at the second floor level, and thereafter, the carriage is to be sent from the second to the third floor at which the screw must move still further upwardly.

The closing of the solenoid switch MS establishes a circuit from the main line 31 through conductor 52, the armature of the switch MS, the conductor 53, switch 33, which is then closed because the screw is down, through over-travel switch 35, conductor 54, the armature of switch SDN, through the winding of switch SUP and through the circuit breakers S5 to the main line 30 which starts the motor 12 to move the screw upwardly until it 4 is centered, whereupon switch 33 opens to break circuit and stop the motor 12.

When the carriage is in close proximity to the second floor to which it has been sent, the slow down switch 2USD will be actuated which will break the circuit through and stop the main motor 6, and a new circuit through the screw up switch SUP will then be established as follows:

From main line 31 through the armature of relay 24, conductor 46, switch 2USD and the up stop switch ZUST, conductor 56, conductor 57, switch 35, conductor 54, the armature of screw down switch SDN through the winding of screw up switch SUP and through the circuit breakers to the main line 30. This starts the motor 12 to run the screw 7 up and thus continue the upward movement of the carriage but at a very slow rate until it is substantially precisely at the level of the second fioor where it is to stop, whereupon the up stop switch ZUST will open which will stop the motor 12. When the switch ZUST is opened, it will also break the circuit which has maintained relay 24 energized and restore it to its normally open position, as shown in Fig. 11.

Assuming that the carriage is now at the second floor but is desired at the third floor for sending a load to the first floor, appropriate signals may be provided at each floor by means of which an operator at any floor where the carriage is desired but is not there, may press a button or otherwise operate the signals on the other floors so that an operator on the floor where the carriage is located may send it to the floor where it is desired.

The operator on the second floor having received such a signal from the third floor, will press push button switch 2-3 which will energize the relay 27 through conductor 58 running from main line 36 through the winding' of relay 2'7, switch 2--3, conductor 59, switch 3UST, conductor 60, relay 29, conductor 61, relay 23, conductor 62, relay 26, conductor 63, relay 25, conductor 64, relay 24 and conductor 65 to main line 31. The closing of the relay 27 maintains it energized, in the same manner as explained in connection with the relay 24, after the push button 2-3 is released. Bearing in mind that the carriage now starting on its trip from the second floor to the third floor, was previously sent to the second floor from the first floor, and hence the leveling screw is in the up position and must be centered before it reaches up slow down switch SUSD. The closing of the switch 2-3 connects conductor 66 and conductor 67 with the main line 31. Following conductor 67 in Fig. 11 will show that it is in an open circuit. But following conductor 66 will show that it runs through switch 3USD, conductor 68, conductor 47, up over-travel switch 48, the armature of switch DN, the winding of switch UP to main line 30, through circuit breakers 50, thus energizing the UP switch and starting the main motor in a direction to raise the carriage. When switch UP is closed, switch MS is also energized and closed. Bearing in mind that the leveling screw is now in the up position and switch 32 is closed while 33 is open, the following circuit is established:

From main line 31 through conductor 52, switch MS, conductor 53, switches 32 and 34, conductor 69, the armature of switch SUP, the winding of switch SDN, and thence through the circuit breakers 55 to main line 30, thus energizing switch SDN which starts the motor 12 to move the screw'downwardly until it is centered and switch 32 is automatically opened. The carriage moves upwardly until up slow down switch 3USD is actuated which breaks the circuit running to switch UP and stops the main motor. At the same time, the movement of switch 3USD establishes a circuit from main line 31 through conductor 67, switch 3USD, switch 3UST, conductor 57, switch 35, conductor 54, the armature of switch SDN, the winding of switch SUP and thence to main line'30. Thus, switch SUP is energized and the motor 12 is started to move the screw upwardly. This movement continues until the up stop switch 3UST is actuated. This breaks the circuit through switch SUP to stop motor 12, and it also breaks the circuit through the relay 27 and restores said relay to the position shown in Fig. 11.

The leveling screw 7 is now in the up position but, when the elevator is started from the third floor to either the first or second floor, a circuit will be established through switch SDN which will start motor 12 and move the leveling screw downwardly until switch 32 is automatically opened when the screw is centered. A circuit will also be established through the switch DN which will start the main motor to lower the carriage.

Assuming that button 3-1 is pressed to send the carriage to the first floor, this will energize the relay 28 through conductor 70 running from main line 30, thence through push button 31, conductor 71, down stop switch IDST, conductor 72, relay 29, conductor 73, relay 27, conductor 62, relay 26, conductor 63, relay 25, conductor 64, relay 24 and conductor 65 to main line 31. Relay 28 will remain closed after push button 31 is released in the same manner as explained in connection with relays 24 and 27.

The closing of relay 28 connects conductors 76 and. 77 with main line 31 but the circuit through the conductor 76 is open, as will be seen by following it a short distance. Conductor 77, however, establishes a circuit to main line 36 as follows:

Through conductor 78, down slow down switch IDSD, conductor 79, through down over-travel switch 80, the armature of switch UP, conductor 81, through the winding of switch DN, and thence to main line 39. This closes switch DN which starts the main motor to lower the carriage. The closing operation of the switch DN also closes switch MS through the armature of switch DN and conductor 51. Since the screw is in the up position and switch 33 is therefore open and 32 is closed, a circuit is established from main line 31 through conductor 52, the armature of switch MS, conductor 53, switches 32 and 34, conductor 69, the armature of switch SUP, through the winding of switch SDN, and thence to main line 30 to operate switch SDN and start the motor 12 in a direction to run the screw downwardly until switch 32 is opened by the centering thereof.

The carriage continues to run down until it actuates down slow down switch IDSD which breaks the circuit through the main motor 6 and establishes a new circuit from main line 31 through relay 28, conductor 76, conductor 82, switch lDSD through switch IDST, conductor 83, switch 34, conductor 69, the armature of switch SUP, through the winding of switch SDN to main line 30 and thus close switch SDN and energize the motor 12 to start moving the screw downwardly. The carriage moves slowly downwardly until it is substantially at the level of the first floor when down stop switch lDST is actuated thereby which breaks the circuit through the motor 12 and also the circuit through relay 28 thereby restoring it to the position shown in Fig. 11.

Similar circuits are shown in connection with each of the other push buttons and the relays associated therewith but it seems unnecessary to encumber the description with details thereof.

Since most codes require that some means be provided at each operational level for shutting oif the power to the elevator, we have shown diagrammatically in Fig. 1, along with each of the two push button switches for operating the elevator, a third switch 84. The switches 84 are in series with each other and serve to connect the source of power with the lines 30 and 31 shown in Fig. 11. Thus, by actuating any of the switches 34, the power lines to the control apparatus are opened, and when it is desired to resume operation of the elevator each of these switches must be closed. They form no part of our invention and, therefore, are not illustrated in the drawing.

When any of, the push button switches is pressed to send the carriage from one floor to any other floor, it

opens all the circuits which otherwise mightbe established by pressing any of the other operating buttons and renders the relays associated with said other buttons inoperative.

In order to make the explanation of our invention as simple as possible, we have illustrated and described it in connection, with only three floors, but it is obvious that it might be applied to an elevator serving any number of floors.

Furthermore, while we have shown certain switches actuatedv by means on the carriage, because it. is probably the best and cheapest way to accomplish this end, it must be understood that these switches could be actuated by other means correlated with the movements of said carriage.

What we claim is:

1. In an elevator serving a plurality of floors, the combination with a carriage having a pulley on the top thereof, of a cable cooperating with said pulley and having one end thereof secured to a winding drum; a main, reversible motor for driving said drum; an elongated, vertically disposed screw having the other end of said cable attached to the lower end thereof; a nut cooperating with said screw and supported on a bearing at a fixed elevation; a second reversible motor for actuating said screw; a first switch actuated by means correlated with the movements of said carriage for stopping said main motor when said carriage is in close proximity to the floor at which it is to stop and starting said second motor to drive said nut in a direction which will move said screw in a direction to continue the movement of said carriage; and a second switch actuated by said means for stopping said second motor when said carriage. is substantially precisely at the floor level where it is to stop.

2. In an elevator servinga plurality of floors, the combination with a carriage having a pulley on the top thereof, of a cable cooperating with said pulley and having one end thereof secured to a winding drum; a main, reversible motor for driving said drum; an elongated, vertically disposed screw having the other end of said cable attached to the lower end thereof; a nut cooperating with said screw and supported on a bearing at a fixed elevation; a second reversible motor for actuating said screw; manually actuated switches at each floor for selectively starting said main motor to move said carriage to any other floor, and simultaneously to start said second motor to effect a centering of said screw in said nut; a first switch automatically actuated by the centering of said screw for stopping said second motor; a second switch, actuated by means correlated with the movements of said carriage when in close proximity to the floor at which it is to stop, for stopping said main motor and starting said second motor to drive said nut in a direction which will move said screw in a direction to continue the movement of said carriage; and a third switch actuated by said means for stopping said second motor when said carriage is substantially precisely at the floor level where it is to stop.

3. In an elevator serving a plurality of floors, the combination with a carriage, of means including a main, reversible motor, for raising and lowering said carriage at substantial speed throughout the major portion of its travel from one floor to another; means, including a second, reversible motor, for raising and lowering said carriage at comparatively slow speed when in operation; a first switch actuated by means correlated with the movements of said carriage, when in close proximity to a floor at which it is to stop, for stopping said main motor and starting said second motor; and a second switch, actuated by said means when said carriage is substantially precisely at the floor level where it is to stop, for stopping said second motor.

4. In a device for stopping, at a precise level, the carriage of an elevator of the cable type; the combination with an elongated, vertically disposed screw provided at the bottom thereof with means for suspending said carriage therefrom by means of said cable; of a nut cooperating with said screw; a fixed bearing on which said nut is rotatably supported; a reversible electric motor for driving said nut in either direction for raising and lowcn ing said screw; a first switch for starting said motor to raise said screw; a second switch for starting said motor to lower said screw; means cooperating with said switches for opening them and holding them both in open position when said nut is substantially at the center of said screw but closing said first switch when said screw moves downwardly from said center, and closing said second switch when said screw moves upwardly from said center; a third switch for starting said motor to raise said screw irrespective of the position of said first switch; and a fourth switch for starting said motor to lower said screw irrespective of the position of said second switch.

5. In an elevator of the push button type serving a plurality of floors; the combination with a carriage; of a cable from which said carriage is suspended; a first means, including a first electric motor, cooperating with said cable for raising and lowering said carriage at substantial speed; a second means, including a second electric motor, cooperating with said cable for raising and lowering said carriage at substantially slower speed; a plurality of manually operable switches at each floor for selectively energizing said first motor to send said carriage to any of the other floors; first carriage-actuated switches adjacent each floor for automatically de-energizing said first motor as said carriage approaches the floor to which it has been sent and simultaneously energizing said second motor; and second switches actuated by said carriage when it is in close proximity to the level of the floor to which it has been sent for automatically de-energizing said second motor to stop said carriage substantially precisely at said level.

6. The structure set forth in claim 5 in which said second means includes a screw and a nut cooperating with said screw and driven by said second motor.

7. The structure set forth in claim 5 in which said second means includes an elongated, vertically disposed screw having said cable connected thereto; a nut driven by said second motor for raising and lowering said screw; and means for automatically centering said screw in said nut following each leveling of the carriage effectuated thereby.

8. In an elevator of the cable type serving a plurality of floors; the combination with a carriage, of means, including a main reversible motor for raising and lowering said carriage, by means of said cable, at substantial speed throughout the major portion of its travel from one floor to another; an elongated vertically disposed screw having one end of said cable secured to the lower end thereof; a nut cooperating with said screw; a second reversible motor for turning said nut to raise and lower said carriage at comparatively slow speed; first switches actuated by means correlated with the movements of said carriage, when in close proximity to a floor at which it is to stop, for stopping said main motor and starting said second motor; a third switch actuated by means correlated with the movements of said carriage for stopping said second motor when said carriage is substantially precisely at the floor level where it is to stop; and means for automatically energizing said second motor to center said screw in said nut following each leveling operation of said screw and prior to each subsequent leveling operation thereof.

9. The structure set forth in claim 8 together with means for automatically de-energizing said motor when said screw has moved a predetermined distance through said nut in either direction to prevent over-travel thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,305,594 Furlow June 3, 1919 1,961,349 Gordon June 5, 1934 2,499,166 Russell Feb. 28, 1950 

